Ohaeles o



(No Model.)

0. 0. BARLOW.

ROCK DRILL.

No. 344,892. Patented July 6,1886.

cramp or bind itself.

CHARLES O. BARLOWV, OF SAN FRANCISCO, CALIFORNIA.

ROCK-DRILL.

SPECIFICATION forming part of Letters Patent No. 344,892, dated July 6,1 886.

Application filed October 7, 1885.

To (LZZ whom, it may concern:

Be it known that I, GHARLEs O. BARLDW, of the city and county of SanFrancisco, State of California, have invented an Improvement inRock-Drills; and I hereby declare the following to be a full, clear, andexact description of the same.

My invention relates to the class of rockdrills; and my inventionconsists in a novel means by which the drill-bit is positively retractedfrom the bottom of the hole, and allowed to spring forward again betweentheintervals of the blows.

It consists,further,in thepeculiar means for mounting the drill, wherebyit is adapted to be thus retracted without interfering with its rotarymovement or its position when receiving the blow; in apeculiar chuck inwhich the drill is mounted, and in the general combination of operativeparts, all of which I shall hereinafter fully describe by reference tothe accompanying drawings, in which Figure 1 is an elevation of myrock-drill, the lower portion of the tubular socket c and the hollowarbor M being in section. Fig. 2 is a View of the chuck O.

It is usual in machine or power drills to hold the drill constantly tothe base of the hole. IVhere the rock is seamy, the drill has a tendencyto go off at an angle, and thus This is caused by the seam, which makesthe rock immediately adjacent to or in front of it break off at anangle, and the end of the drill-bit, being always against the base ofthe hole, has no opportunity to correct this and to straighten the hole,its ordinary rebound not being sufficient for this purpose; but bypositively retracting the drill it is enabled to come backin contactwith the high point of the hole just behind, and thus to straighten it.Again, where a downhole is being made, if the drill remains in the baseof the hole, it is very difficult to reduce the pulverized and brokenpieces of rock to a pulp; but by positively withdrawing the drill ashort distance between blows it will permit the water which is pouredinto the hole to get to the bottom, and reduce the debris to a pulp ofsuch consistency that it can readily be discharged.

1 have herein shown my invention in con- Serial No. 179 266. No model.)

nection with the parts of a rock-drill now in use, and which will needbut a brief de scription.

A is the supporting column or pillar, to which the crossbar B isconnected by a suitable swivel-joint.

G is the body-bar of the drill,provided with a cross-head, c, and movedforward or back by means of a screw, D. In the lower portion of thebody-bar is the driving-shaft E, to which is secured the crank-wheel F.In the lower back portion of the body bar is pivoted the. hammer-holderG, in the socket of which is secured the handle it of the hammer H. Onthe shaft E is secured a cam, I, which bears against the pivotedhammerholder and forces the hammer back. The blow of the hammer isdelivered,under the influence of the spring J, on the rod 3', pivoted tothe hammer-holder.

On the other end of the shaft E is a worm,

which meshes with a gear on a short countershaft carrying achain-pulleyJL. The wormgear and the counter-shaft I have not deemed itnecessary to show. From the pulley K extends an endless chain, L, to apulley, m, above. These are all parts of a machine now in use.

The cross-head c of the body-bar is formed with a tubular socket, c, inwhich is seated and adapted to rotate a hollow arbor, M, which is heldin its seat by a nut, m, on its forward end, and has on its rear end thechainpulley m, hereinbefore described, and by which said arbor isrotated. The arbor has an angular hole through it, in which is seatedand adapted to slide aspindle, N, the rear end of which extends behindthe arbor and is adapted to receive the blow of the hammer. As the holein the arbor is angular in cross-section, the spindle is made likewisein cross-section, so that by the rotation of the former the latter isalso rotated, though still adapted to have its longitudinal movement.This might be accomplished also by a spline or feather, or otherwell-known mechanical eXpedients. At the forward end of the spindle isformed or secured a chuck, O, the peculiarity of the construction ofwhich I shall presently describe. In this chuck is secured the drill-bitP. On the spindle N is formed or secured a grooved flange, R, in whichis seated a strap, S.

T is a red, the rear end of which is guided loosely in a socket, t, onthe body-bar, and is limited by a pin, The forward end of the rod isconnected with the strap S, and its body is provided with a slot, t

Pivoted on a short shaft, to, is a lever, U, the upper end of whichengages the slot t in the rod T. Its lower end is engaged by smallantifriction rollers V on the disk 22, secured to the crank-wheel F.

Around the spindle N, between the flange B and the end or nut of thearbor, is a spring, W.

The operation of the drill, as far as described, is as follows: Therotation of the crank-wheel F forces back, through the cam I and thepivoted hammer-holder G, the hammer H, which, when relieved by the cam,is thrown forward to deliver its blow under the influence of the springJ. The rotation of the power-shaft E, through the devices described,rotates the arbor M, in which the spindle N is seated, and consequentlyrotates said spindle and drill. Thesmall anti-friction rollers V on thecrankwheel, coming successively in contact with the lowerend of thelever U, cause said lever to draw back the rod T, which, through thestrap S, draws back the spindle N and the drill-bit. When the lever U isrelieved from the roller, the spring XV throws the spindle and d rillfor ward again. This movement of retracting and throwing the drillforward again takes place in the intervals between the blows of thehammer. To regulate the amount of retraction of the drill-bit I maymake, as shown in Fig. l, the connection between the rod T and the strapS an adjustable one by thread ing the end of said rod, passing itloosely through the lower end of the strap, and fitting on the threadedend of the rod, on each side of the strap, the nuts X. By adjustingthese nuts the rod T may be moved forward or moved back farther, whichmovement alters the position of the lever U, causing the rollers V tocome to their engagement with it sooner, and to thereby move it farther,or the reverse of this operation.

The chuck 0 consists of two plates, one of Which, 0, has an angulargroove, 0, corresponding to the shape of the drill-bit. The

other plate, 0, is flat, and is secured to the first plate by bolts 0thereby binding the drill-bit between the two plates, as shown in Fig.2. p I

Having thus described my invention, what I claim'as new, and desire tosecure by Letters Patent, is

1. In a rock-drill, the rotating arbor M,

'having an angular hole or socket through it,

the spindle N, mounted in said arbor and adapted to have a longitudinalmovement therein and to be rotated thereby, and a chuck on the spindlefor holding the drill-bit, in combination with the pivoted lever U, thecrank or power wheel F, having rollers V, engaging said lever, thesliding rod T, engaged and operated by the lever, a connectionbetw eenthe rod and the spindle, whereby the spindle is retracted, and a springon said spindle for throwing it forward again, all arranged and adaptedto operate substantially as herein de scribed.

2. Ina rock-drill, the rotating hollow arbor M, the spindle N, seated insaid arbor and retated thereby, said spindle having a longitudinalmovement in the arbor and. adapted to receive the blow, a chuck on thespindle for holding the drill-bit, and a grooved flange on said spindle,in combination with the crank or power wheel F, having rollers V, thepivoted lever U, engaged by said rollers, the sliding rod T, engaged bythe lever, and the-strap S, connected with the rod and seated on thegrooved flange, and the springWV around the spindle, substantially asherein described.

3. In a rock-drill, the body-bar 0, having a socket, c, in its top, thedriving-shaft E in the bottom of the body-bar, having a crankwheel, F,the vibrating hammer H, the endless chain L, and mechanism by .which thehammer and chain are operated from the driving-shaft, in combinationwith the hollow arbor M in the socket a, and having a pulley, m,through'which it is rotated, the spindle N, mounted and adapted to slidein'said arbor, to be rotated thereby, and to receive the blow of thehammer, the grooved flange R and the chuck O on the spindle, therollersV on the wheel F, and the pivoted lever U, engaged by therollers, the sliding rod T, engaged by the lever, the strap S, securedto the sliding rod and seated on the grooved flange of the spin dle, andthe spring WV upon the spindle, all arranged and adapted to operatesubstantially as herein described. I

4. In arock-drill,thelongitudinally-inoving and rotating drill-carryingspindle N, having a grooved flange, R, and a spring, WV, in combinationwith the pivoted lever U, the rollers Von the driving-wheel, engagingsaid lever, the sliding rod T, engaged by said lever, the strap S,seated in the grooved flange, and an adjustable connection between saidstrap and the sliding rod,whereby the longitudinal movement of thespindle is regulated, substantially as herein described.

and rotating drill-carrying spindle N and the hollow arbor M in thesocket c, in combination with the chuck 0, comprising the plate 0,having an annular groove corresponding to the angularity of thedrill-bit, and the flat plate 0, bolted to the plate 0, and clamping thedrill-bit in the groove of said plate, substantially as hereindescribed.

In witness whereof I have hereunto set my hand.

CHARLES O. BARLOIV. Witnesses:

O. D. CoLn, J. H BLooi).

ICC

